Two of Valve’s most recognizable games are now available for the Android-powered NVIDIA Shield, after being teased last week to several online publications. The above crowbar — a tool that is used throughout Half-Life 2 — was sent to AndroidPolice‘s Michael Crider, depicting both an NVIDIA Shield device and the lambda, which represents the Half-Life series.

Besides Half-Life 2, Valve also released Portal for Android today. Both games are on sale at the Play Store for $9.99, though they are only compatible with the NVIDIA Shield.

Compatibility with other Android devices seems extremely unlikely. These games are almost certainly the result of a partnership between NVIDIA and Valve, and as such will likely remain exclusive to the Shield. Additionally, both games would be difficult to play without a game controller.

That probably won’t stop hackers from trying to bring the game to other devices; in the past, we’ve seen efforts to port games to Android, though they’ve never gotten far enough to be considered stable.

Both games look fine running on the Shield, though neither represent the latest in terms of graphics. Portal, released in 2007, definitely has the visual edge on Half-Life 2, released in 2004.

So: will the release of these two games — both of which any hardcore gamers have almost certainly already played — be enough to push sales of the NVIDIA Shield? Or will NVIDIA’s attempt to create an Android-powered competitor to other handheld game consoles continue to slump? My bet is on the latter, especially considering that releases like these tend to focus on PC gamers who might have custom-built rigs and therefore already be familiar with NVIDIA’s custom GPUs.

If NVIDIA hopes to compete with the PlayStation Vita and the Nintendo 3DS, they need to bring games and experiences that are only possible on their handheld, and not games that have been playable for the better part of a decade.